Linux From Scratch - Version 6.3

Chapter 6. Installing Basic System Software

6.12. GCC-4.1.2

The GCC package contains the GNU compiler collection, which
includes the C and C++ compilers.

Approximate build time:22 SBU testsuite included

Required disk space:681 MB testsuite included

6.12.1. Installation of GCC

Apply a sed
substitution that will suppress the installation of libiberty.a. The version of libiberty.a provided by Binutils will be used
instead:

sed -i 's/install_to_$(INSTALL_DEST) //' libiberty/Makefile.in

The bootstrap build performed in Section 5.4, “GCC-4.1.2 -
Pass 1” built GCC with the -fomit-frame-pointer compiler flag. Non-bootstrap
builds omit this flag by default, so apply the following
sed to use it in
order to ensure consistent compiler builds:

sed -i 's/^XCFLAGS =$/& -fomit-frame-pointer/' gcc/Makefile.in

The fixincludes
script is known to occasionally erroneously attempt to "fix" the
system headers installed so far. As the headers installed by
GCC-4.1.2 and Glibc-2.5.1 are known to not require fixing, issue
the following command to prevent the fixincludes script from running:

sed -i 's@\./fixinc\.sh@-c true@' gcc/Makefile.in

GCC provides a gccbug
script which detects at compile time whether mktemp is present, and
hardcodes the result in a test. This will cause the script to fall
back to using less random names for temporary files. We will be
installing mktemp later, so the following sed will simulate its
presence:

sed -i 's/@have_mktemp_command@/yes/' gcc/gccbug.in

The GCC documentation recommends building GCC outside of the source
directory in a dedicated build directory:

A few unexpected failures cannot always be avoided. The GCC
developers are usually aware of these issues, but have not resolved
them yet. In particular, the libmudflap tests are known be particularly
problematic as a result of a bug in GCC (http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20003).
Unless the test results are vastly different from those at the
above URL, it is safe to continue.

Install the package:

make install

Some packages expect the C preprocessor to be installed in the
/lib directory. To support those
packages, create this symlink:

ln -sv ../usr/bin/cpp /lib

Many packages use the name cc to call the C compiler. To
satisfy those packages, create a symlink:

ln -sv gcc /usr/bin/cc

Now that our final toolchain is in place, it is important to again
ensure that compiling and linking will work as expected. We do this
by performing the same sanity checks as we did earlier in the
chapter:

If everything is working correctly, there should be no errors, and
the output of the last command will be:

attempt to open /lib/libc.so.6 succeeded

Lastly, make sure GCC is using the correct dynamic linker:

grep found dummy.log

If everything is working correctly, there should be no errors, and
the output of the last command will be (allowing for
platform-specific differences in dynamic linker name):

found ld-linux.so.2 at /lib/ld-linux.so.2

If the output does not appear as shown above or is not received at
all, then something is seriously wrong. Investigate and retrace the
steps to find out where the problem is and correct it. The most
likely reason is that something went wrong with the specs file
adjustment. Any issues will need to be resolved before continuing
on with the process.